Millie has confirmed the relationship via social media over the past few months.
The couple was first seen together early in November, reportedly first meeting in the Maldives when on vacation. At the time, Joseph shared a photo from the trip wich had Millie in it!
"Great time in the Maldives with family and friends," he wrote on Instagram.
Last week, Millie added fuel to the fire by sharing a photo of herself wearing a Wigan Warriors jersey, which is the team that Joseph plays for.
But of course it didn't end there. Millie commented on a recent photo of Joseph, writing "yessss! ❤️," and Joseph responded with a heart.
Last month, the pair went on a romantic walk together sharing photos with some adorable doggos along the way.
But the CLINCHER is that they're totally in love, and not afraid to say it.
Millie posted a very intimate cuddle shot on Snapchat with the text "Ly" meaning "love you"...
We're FEELING this!